What’s Vulnerable › Vulnerabilities
CVE-2025-38071: x86/mm: Check return value from memblock_phys_alloc_range()
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-06-18 · updated 2026-06-17
Description
In the Linux kernel, the following vulnerability has been resolved: x86/mm: Check return value from memblock_phys_alloc_range() At least with CONFIG_PHYSICAL_START=0x100000, if there is < 4 MiB of contiguous free memory available at this point, the kernel will crash and burn because memblock_phys_alloc_range() returns 0 on failure, which leads memblock_phys_free() to throw the first 4 MiB of physical memory to the wolves. At a minimum it should fail gracefully with a meaningful diagnostic, but in fact everything seems to work fine without the weird reserve allocation.
Affected products
- Debian Linux: 11.0
- Linux kernel: before 6.1.141; from 6.2 before 6.6.93; from 6.7 before 6.12.31; from 6.13 before 6.14.9 — fixed in 6.1.141, 6.12.31, 6.14.9, 6.6.93
How to fix
Upgrade to a fixed version: Linux kernel 6.1.141, 6.12.31, 6.14.9, 6.6.93. Check the vendor advisory for mitigations.
References
- https://git.kernel.org/stable/c/631ca8909fd5c62b9fda9edda93924311a78a9c4
- https://git.kernel.org/stable/c/8c18c904d301ffeb33b071eadc55cd6131e1e9be
- https://git.kernel.org/stable/c/bffd5f2815c5234d609725cd0dc2f4bc5de2fc67
- https://git.kernel.org/stable/c/c6f2694c580c27dca0cf7546ee9b4bfa6b940e38
- https://git.kernel.org/stable/c/dde4800d2b0f68b945fd81d4fc2d4a10ae25f743
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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